Characterisation, prevalence and severity of skin lesions caused by ophidiomycosis in a population of wild snakes.

Ophidiomycosis is an emerging infectious disease affecting wild snakes in the Northern Hemisphere. Recently confirmed in Great Britain, the prevalence, severity and significance of ophidiomycosis has yet to be characterised in free-living snakes at a population level in Europe. Therefore, a population of barred grass snakes (Natrix helvetica) in eastern England was monitored for three seasons (May 2019 to October 2021), to investigate the prevalence (25.5%; 191/750 snakes) and severity of skin lesions and their aetiology. The most frequently observed skin lesion characteristics were changes in scale colour, crusting, and scale margin erosion. The majority of such lesions (96.9%; 185/191 snakes) was observed on the ventral surface along the length of the body. The severity of skin lesions was considered mild in more than half of the cases (53.1%; 98/191 snakes). Predominantly, skin lesions were observed in adult snakes (72.8%; 139/191 snakes). Combined histological examinations and qPCR tests of skin lesions from N. helvetica sloughs and/or carcasses confirmed a diagnosis of ophidiomycosis. Further targeted surveillance, supported by molecular and histological examinations to confirm skin lesion aetiology, is required to determine the extent to which our findings reflect the occurrence of ophidiomycosis in populations within wider landscapes.

REPEATED SAMPLING OF WILD INDIVIDUALS REVEALS OPHIDIOMYCES OPHIDIICOLA INFECTION DYNAMICS IN A PENNSYLVANIA SNAKE ASSEMBLAGE.

Ophidiomyces ophidiicola is an emerging fungal pathogen associated with infections in snakes across North America. Although documented in Pennsylvania, O. ophidiicola has not been found at Powdermill Nature Reserve (PNR) in southwestern Pennsylvania, where the snake assemblage has been studied since 2002 and several species have recently declined. We surveyed for O. ophidiicola and putative ophidiomycosis at PNR. We screened five species of free-ranging, wild snakes (n=34) for suspected ophidiomycosis by visually checking for dermatitis and swabbing for the presence of O. ophidiicola DNA. We found a moderate prevalence of snakes with skin lesions (n=15) but a low prevalence of snakes with O. ophidiicola DNA in traditional PCR assays (n=2). Both positive snakes belonged to the same species and only one presented with lesions. When quantitative PCR screens were performed on duplicate swabs, 19 snakes were positive for O. ophidiicola DNA, with positive individuals in two species. Mark-recapture methods revealed seasonal variability in disease dynamics for sampled snakes. One individual presented with less than five skin lesions and tested negative in May 2020, had more than five lesions with a high fungal DNA load in June 2020, and no lesions with a low fungal DNA load in July 2020. We also found that snakes sampled from under the same cover object at the same time either all tested positive or all negative, including one instance involving two species. Our results underscore the value of using multiple screening techniques for O. ophidiicola surveillance and repeated sampling of individuals to understand the dynamics of ophidiomycosis in wild populations as compared to single method and single timepoint approaches.

Catalogue of herpetological specimens of the Ewha Womans University Natural History Museum (EWNHM), Republic of Korea.

The herpetology collection of the Ewha Womans University Natural History Museum (EWNHM) represents one of the oldest and largest institutional collections in the Republic of Korea. The specimens deposited in the EWNHM represent a major historical collection of the native herpetofauna, both in species diversity and time span. However, the full inventory of the herpetology collection has never been conducted and thus the collection has received little attention from researchers. Here, the first full account of the herpetology specimens held at the EWNHM is provided, with voucher information for all documented specimens to make the collection accessible for future studies.

Common midwife toad ranaviruses replicate first in the oral cavity of smooth newts (Lissotriton vulgaris) and show distinct strain-associated pathogenicity.

Ranavirus is the second most common infectious cause of amphibian mortality. These viruses affect caudates, an order in which information regarding Ranavirus pathogenesis is scarce. In the Netherlands, two strains (CMTV-NL I and III) were suspected to possess distinct pathogenicity based on field data. To investigate susceptibility and disease progression in urodeles and determine differences in pathogenicity between strains, 45 adult smooth newts (Lissotriton vulgaris) were challenged via bath exposure with these ranaviruses and their detection in organs and feces followed over time by PCR, immunohistochemistry and in situ hybridization. Ranavirus was first detected at 3 days post infection (p.i.) in the oral cavity and upper respiratory mucosa. At 6 days p.i, virus was found in connective tissues and vasculature of the gastrointestinal tract. Finally, from 9 days p.i onwards there was widespread Ranavirus disease in various organs including skin, kidneys and gonads. Higher pathogenicity of the CMTV-NL I strain was confirmed by higher correlation coefficient of experimental group and mortality of challenged animals. Ranavirus-exposed smooth newts shed virus in feces intermittently and infection was seen in the absence of lesions or clinical signs, indicating that this species can harbor subclinical infections and potentially serve as disease reservoirs.